Virgin Amazon jungle is burned to clear land for cattle pasture, on a private ranch near the Jarina Indian reserve October 1, 2006.

BRASILIA - Cattle ranchers are far bigger culprits in Amazon deforestation than soy farmers, a study showed on Tuesday, as the environmental record of Brazil's commodity exporters comes under increasing international scrutiny.

The study, produced jointly by environmental groups and the soy industry, showed that only 12 of 630 sample areas deforested since July 2006 -- or 0.88 percent of 157,896 hectares (390,000 acres) -- were planted with soy.

By comparison, nearly 200 were converted into pasture land for cattle. The rest of the deforested areas had not yet been put to use.

"The big villain of Amazon destruction is cattle ranching," said Paulo Adario, Amazon campaign coordinator with Greenpeace, one of the groups that sponsored the report.

Each year country-sized chunks of the world's largest rain forest are devastated, although the rate has fallen sharply from a few years ago and preliminary data shows it fell further in the past 10 months.

In addition to loggers, ranchers and peasants, large-scale farmers are often blamed for contributing to the devastation as Brazil's agricultural frontier has expanded due to strong foreign demand for the country's commodities in recent years.

Brazil is the world's biggest beef exporter and the second-largest exporter of soy, much of which is bought by China.

Adario said the size of deforested plots had been falling consistently in recent years. That suggests that soy farmers, who require large areas to be efficient, were no longer involved directly in clearing forest.

SOY ACCORD

Brazil's soy industry, with exports of $18 billion last year, agreed in July 2006 not to trade soy from deforested areas.

That accord helped prevent farmers from clearing large, new areas, the authors of the report said.

"Soy is no longer a big threat to the Amazon," said Carlo Lovatelli, head of the soy industry association Abiove.

Foreign farm competitors in the United States and Europe often criticize Brazilian exports, such as sugar and beef, for contributing to deforestation.

Lovatelli acknowledged the accord did not cover about 10 percent of Brazil's soy output and that mechanisms to control its implementation were still inadequate.

Asked what would happen to a farmer who planted soy illegally on deforested land, Lovatelli said, "He'll sell to a Chinese trader on the spot market."

Some environmental economists say the expansion of soy has been to blame for deforestation by displacing cattle ranchers deeper into the Amazon in search of cheaper land.

Still, Environment Minister Carlos Minc said the accord was a good first step.

"It's a model for other sectors to follow," said Minc, adding he was eyeing a similar accord with the beef industry.

Brazil's government, which last year abandoned years of opposition to deforestation targets, aims to reduce deforestation in the 12 months through July to about 9,500 square km (3,667 square miles) from 11,900 square km (4,595 square miles) the year before.